In the past resistance apparatus of varying types have been developed. Thus, apparatus has been developed to facilitate training in various sports, such as in tennis, and hitting a baseball. One such device is shown in U.S. Pat. No. 2,134,451. This device includes a pulley block which is adapted to be mounted to a wall, a rope which passes over the sheave in the pulley block and which has one end secured to the block, and a second pulley block, an intermediate portion of the rope engaging the sheave on the second pulley block, which second pulley block carries a weight. A baseball bat or tennis racket may be secured to the free end of the rope, and the swinging of the bat or racket is resisted by the weight carried by the second pulley block. While this device may be successful for its intended purposes, it has the disadvantages in that it must be more or less permanently secured to a wall, and it only has limited applications.
U.S. Pat. No. 4,109,907 discloses a home exercise device which includes clip means for removeable engagement over the upper edge of a door, which clip means support pulley blocks to which weights and resistive training devices may be secured. While this device may be useful for its intended purposes, it lacks versatility and requires that a door be utilized.
It has been suggested that a resistance weight training device may be secured within a door frame and this is shown in U.S. Pat. Nos. 4,243,219 and 4,344,618. Neigher one of these patents discloses a device which may be readily carried from one location to another. U.S. Pat. No. 4,619,453 also discloses a door frame resistance training device, but this device is unduly complicated.
U.S. Pat. No. 4,290,598 discloses a resistance or tension exerciser which may be supported from the joists of a ceiling.
Other apparatus has been developed for use in rehabilitation of injuries and for physical thereapy. However, most rehabilitative apparatus is either very specialized, expensive, or both.